Right, thanks for all the replies.
Obviously I need to get a hold of a voltmeter.
Right I'm back in the marina and back on the shoreline, so everythings ok until we take it out again.
As far as i can tell, the starter battery is being charged up as we cruise. It seems that the domestic batteries are not being charged as we cruise. I have come to this conclusion because when I put the battery chargers back on, one was full and one was dead.
Is it normal to have 2 seperate altenators?
If so I guess one isn't working?
I will come back with some more information as soon as i can, thanks!
Oh and the only switches i have is the one that switches on the inverter and one which says shoreline/off/inverter
Oh also, We decided to turn the inverter off and only really used the water pump, and yes it worked fine.